The edge portal was installed by sub-bots before anyone was sent to the Edge. After a while explorers sent by Murtaugh reverse-engineered the portal so that humans could use it. One of these explorers likely stayed at the cliffs until he decided that help wasn't coming, and he then went to the tunnels mentioned earlier.

Then at least four other people came through the cliffs, and at some point, sub-bots reverse-engineered portal 2/32.

The cliffs are a series of horizontal rooms directly over the void. A rusted edge portal can be found here.

A note from a previous explorer can be found around the edge of the wall. In Submachine 6 the leftmost venting cover can be taken off, allowing access to the tunnels.

In Submachine 10 the edge portal is shattered by a karma portal. The pipe can be climbed up on like in Sub6 and in the SubVerse, but this time the stone wall is chipped away to reveal a porthole to access a defense system corridor, particularly the S.H.I.V.A. access point.

The wall containing the tunnel grates has chipped away on the left side, leaving only the right pair of entrances. These can be removed, revealing a previously unseen part of the tunnels.

The image on the screen.

In Submachine Universe, the rusted portal has been replaced by the lab portal found in Sub4 and other parts of the subnet. The player cannot access the tunnels, but in the leftmost screen an extra slab of stone has appeared, offering a karma portal to the resin room. A device resembling a physician's scale sits to the left of the rightmost room, which contains a large metal pipe. The scale device possesses a viewing screen that displays a photograph by Asia Sliwiak.